I got one of these in 45x16and it easily fits my BSA Scorpion SE with Viper 4-16x50(same scope as on the rig in my avatar which also fits in no prob)with 6in side-wheel attached which makes for a very tall rig but it fits now problem and I haveenough spare room I would go with the 13in in retrospect but the build is good and the pockets on the side a really handyfor fill probes, notes, pellets, mags, etc.